Water effectively. Unless the water reaches the roots where it can be taken up by the plant, you waste both time and water. Let the sprinkler run until water runs off, turn off the sprinkler to let water soak in, then water again, repeating until the root zone is wet. Several cycles may be necessary.
Control fungal diseases – which flourish in hot, dry, and humid weather – by keeping irrigation water from standing on foliage. The best time to water is early morning or late at night, so that morning sun can dry water drops from foliage. Watering in early evening keeps foliage damp all night, encouraging the spread of fungal spores. Drip irrigation is preferable to overhead irrigation, because water is delivered to the roots and doesn’t contact the foliage.
LAWN CARE
Established fescue lawns naturally go semi-dormant in the heat of July. Established fescue can survive up to three weeks without water, but will need a drink if it doesn’t rain by then! Water only when grass shows sign of wilt (footprints show when grass is walked on). Fescue planted last fall will need watering every week. Call for a Fescue Lawn Maintenance Calendar.
TREES & SHRUBS
Propagate shrubs by rooting cuttings. Semi-hardwood cuttings of Azalea, Camellia, and Holly can be taken this month. The wood should be hardened enough that the stem breaks when bent. Call for information on rooting cuttings.
Prune off spent crape myrtle blossoms to prolong the flowering period. Sooty Mold will make the leaves appear dark and sooty or almost uniformly charcoal gray. Sooty mold grows on the sticky leftovers of a May/June aphid feast. Control the aphids, and the mold will wash off. Powdery Mildew makes the leaves appear grey and powdery. It’s a common problem which disfigures the foliage but doesn’t kill the tree.
Keep shade trees watered. Shade trees in declining health may simply be thirsty. Water deeply, to soak the soil 4-6″ deep around the drip line of the tree.
Hand-pick bagworm bags on evergreens. Pesticides are not effective once the caterpillars are safe in their bags.
Remove vigorous upright sprouts growing from tree roots (“suckers”) or from the upper surfaces of tree branches (“water sprouts”). Rub off unwanted sprouts from branches and trunks, to direct the tree’s energy into desirable growth.
ORNAMENTALS
Weed when it’s easy. Weeds are easier to pull when the soil is moist, so wait until after a soaking rain, or irrigate the area first. The roots of desirable plants can be injured by pulling large weeds nearby, so pull those weeds in late afternoon or on cloudy days, and water the area afterward to help injured plants recover.
Start seeds for cool-weather annuals indoors in July/August for fall planting. Try foxglove, pansy, alyssum, snapdragons, ornamental cabbage (kale), and primroses. Pansy seeds germinate well when stored in the refrigerator (not freezer) for 10-14 days before planting.
VEGETABLES & FRUITS
Watch for blossom-end rot on tomatoes. That black rot at the bottom of the fruits is a symptom of calcium deficiency. To help your plants this year, apply a foliar spray of calcium. To prevent the condition next year, add lime to the soil when you plant tomatoes.
WILDLIFE & INSECTS
Put out a bird-bath and keep it filled with fresh water. Birds will pay you back by eating lots of insects!
Think twice about squashing caterpillars; many turn into butterflies. Swallowtail butterfly caterpillars love parsley, so set out a few extra plants to share with them. A pan of moistened pebbles or sand will attract butterflies.
LANDSCAPE IDEA
Think strategy. Now that deciduous trees and shrubs are in leaf, survey your landscape critically. Do you have too much? too little? are plants too low where screening is needed? so tall that a view is blocked? Take photographs and make plans to add or move shrubs this fall. Don’t do it now.
Plant chrysanthemums for fall color. Plant rooted cuttings in flower beds, planters, or tubs on patio. Pinch out the tips of garden mums to encourage lower, compact plants with many flowers.
HOUSEPLANTS
Keep potted plants watered! Plants in pots outside may need daily watering in the heat of summer.
Start stem cuttings of geraniums and leaf cuttings of succulents to be potted for use as house plants this winter.
From: http://www.ces.ncsu.edu/durham/agriculturehorticulture/mg/gardencalendar/jul.php